Continuous catalytic transesterification process, for preparing esters, is carried out in single reactive distillation column with integrated stripper section for alcohol removal

摘要

In a continuous catalytic transesterification process carried out in a reactive distillation column (RDC) with several sections (one being a reaction zone), an open additional section (S2), in the upper region of the RDC (D), is separated from sections (S3, S4) at and below the same height by fluid-impermeable walls (8, 9) and supplies liquid to an evaporator (V2) from which alcohol product is recovered, the residue being recycled as vapor to the RDC. Continuous catalytic transesterification is carried out in a catalyst-containing reactive distillation column (RDC) with several sections containing packing and/or plates. One section is a reaction zone, supplied with a first ester (I) (optionally mixed with a second (produced) alcohol (III)) and (at a higher site) a first alcohol (II). A first evaporator (V1), connected to the RDC base, is supplied with a liquid, from which the second (product) ester (IV) is extracted and the remainder is recycled as vapor to the RDC. An azeotropic mixture of (I) and (III) is condensed in a condenser at the column head, and part of the condensate is supplied to the RDC head and part is supplied together with (I) to the lower inlet site. The novel feature is that an open (in use) additional section (S2), located in the upper region of the RDC (D), is separated from the sections (S3, S4) at and below the same height by fluid-impermeable walls (8, 9) and is connected to a second evaporator (V2), supplied with liquid from (S2), from which (III) is recovered and the remainder of the liquid is recycled as vapor to the RDC. An independent claim is included for the corresponding apparatus, consisting of the RDC as above, including the additional section (S2), fluid-impermeable walls (8, 9) and second evaporator (V2) connected via lines (10, 11).